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I for one always always suggest one try and shoot a variety before making a purchase.
Best thing is to take a Handgun Course and get training. This will not only allow you learn safety, also proper instructions on how different platforms work, pro's and con's, and to actually shoot these varieties.
Too many students showed up with what daddy, big brother, or magazine 'said' they needed. Only to find the gun did not fit them, the controls were difficult - especially under stress, or the recoil was not pleasant.
Always suggested folks not buy until they actually took the class and tried our variety of guns. Some were duplicates - just different stocks. We did this with holsters belts too...
Personally I never warmed up the .40. Students we had never seemed to warm up to either. Sharper recoil in some of the smaller guns, and especially the Polymer.
9mm affords one an affordable ammo choice to promote shooting more to become proficient, in a bunch of platforms with milder recoil.
45ACP has a soft push, many of the ladies really like this in the 1911s, and Rugers.
Funny tho', too many students really like for a first gun a Used Model 10. Used Police trade ins, variety of ammo for different tasks , affordable, always someone who reloaded for them would do so, not ammo dependent, no mag dependent for the gun to run.
I have always said - if a person learns to shoot a Revolver DA, they will be a better shooter no matter what platform they may transition to later on.
Students really liked the dry fire practice. Some made it a fun challenge putting that dime on and going thru a whole cylinder and it not falling off.
"Hey, you said this dry fire dealie with a dime would make me a better shooter...check out THIS target will you?" <big grin with target in hand>
Try before you buy, get proper training. One cannot buy skill and targets.